1999/01/29 by Philippe Bourges
Physics and Astronomy · #cond-mat.supr-con #cond-mat.str-el
published as The gap Symmetry and Fluctuations in High Temperature Superconductors} Edited by J. Bok, G, deutscher, D. Pavuna and S.A. Wolf. (Plenum Press, 1998). 349-371 (Vol. 371 in NATO ASI series, Physics). · To appear in "The gap Symmetry and Fluctuations in High Temperature Superconductors" Edited by J. Bok, G, deutscher, D. Pavuna and S.A. Wolf. (Plenum Press, 1998)
arxiv created 1999/01/29 · arxiv updated 2009/11/30
The spin dynamics of high temperature superconductors measured by inelastic neutron scattering is reviewed. The spin susceptibility evolves a lot with increasing doping from the undoped insulating state to the overdoped metallic state. In the superconducting state, a strong magnetic resonance peak occurs in the spin excitation spectrum whose energy is proportional to the superconducting temperature. In underdoped and optimally doped regimes, normal state antiferromagnetic fluctuations are observed, proving the existence of strong electronic correlations in cuprates. They are characterized by a spin pseudo-gap. In contrast, these dynamical spin correlations vanish in overdoped samples.